luci-base: Fix typos in JsDocs

In some places argument name was renamed but in the JsDoc it's remain old.

Added more typing for string enum fields like:

 @param {string} [type=text]

replaced with:

 @param {"blob"|"text"|"blob"} [type=text]

Signed-off-by: Sergey Ponomarev <stokito@gmail.com>